For both recreational and competitive bicycle riders, the fit of a bicycle and the adjustment of the rider's position on the bicycle are key considerations that directly impact overall performance. Such parameters as comfort, safety, aerodynamic efficiency, power delivery, and endurance are influenced by fit and rider position.
Given the importance of rider fit and position, considerable information and various techniques are available to obtain the proper bike fit when purchasing a bike, and then to adjust the rider's position on the bicycle so selected, taking into account comfort, safety, aerodynamics, and power delivery. By way of example, the book entitled “Zinn & the Art of Triathlon Bikes” (hereinafter referred to as “Zinn”), published in 2007 by VELOPRESS, a trade name for a division of Inside Communications, Inc., provides detailed instructions and illustrations of bike and bike equipment selection and rider positioning on the bike. This is particularly important for triathlon bikes equipped with aerobars as illustrated and described in Zinn, but also applies to road bikes, mountain bikes, hybrids, and other types of bicycles, including stationary exercise bikes. The material most relevant to the present invention appears in Zinn chapters 2, 3, and 13, which is incorporated herein by reference in its entirety.
As taught in Zinn, the process of rider position adjustment includes various position modifications and fine-tuning that are performed to put the rider in the best possible position on the bike. Key adjustments include seeking the best seat position in height and longitudinal location for the bike owner. The longitudinal position is also referred to as fore-aft position of the bike seat or saddle and is illustrated in Zinn at FIG. 2.3 along with the relationship between fore-aft position and seat-tube angle. The term “effective seat-tube angle” refers to the result achieved by positioning the seat in different fore-aft locations as opposed to the neutral position over the seat post, thereby changing what is referred to in the art as the effective seat-tube angle. The actual angle formed between the seat tube and the horizontal plane or level ground, however, remains constant on a given bicycle frame, but the rider experiences the effective angle as though it were the actual seat-tube angle.
Using typical bicycle components, and as illustrated and described in Zinn, the rider's position is optimized, then fixed. That is, the bicycle components are secured in place with clamps, bolts, or the like. Subsequent adjustments may be done periodically by riders based on comfort and performance considerations from riding, or when new equipment is purchased, such as a new seat or new handlebars or aerobars. The problem with this current state of the art is that the optimal seat longitudinal position and corresponding effective seat-tube angle vary during a ride. This occurs, among other reasons, because of changing road conditions such as inclines, which cause the rider to sit upright as opposed to riding in the aerobars or drop bars, and during times in which the rider needs to take in fluids or food, and to stretch or otherwise relax back muscles. The adjustability of longitudinal seat position is also advantageous in allowing the rider to emphasize or recruit different muscle fibers at different times during a ride or race.
Attempts have been made by others to provide for dynamic seat adjustability in response to the desirability of seat adjustment during a ride. The term “dynamic seat adjustability” as used herein refers to the feature of seat adjustability while riding. The prior art devices that provide for dynamic seat adjustability are generally unsuitable for use with many bikes, particularly road racing, triathlon, and time-trial bikes because of the prior art component's weight, size, or aerodynamic drag burdens.
One example of a prior art attempt at solving this problem is U.S. Pat. No. 6,827,397. The device described in the '397 patent does provide dynamic adjustability in longitudinal seat position, but at the expense of creating an awkward and large seat, which is incompatible with existing seats and the desire for minimum weight, volume, and aerodynamic drag. In addition, the device of the '397 patent suffers from complexity in its components and operation. The device includes a large boom which extends well forward of the seat post, a locking system having multiple components, and a release lever located behind the seat, which must be manipulated to adjust the seat position. Not surprisingly, such prior art devices are seldom if ever used, especially in a triathlon, road bike race, or the like.
Other prior art attempts at solving this problem of rider positioning teach away from the present invention. Several leading manufacturers and designers of bicycle seats for use by riders with aerobars have adopted as a design feature a wider or heavily padded nose, or a combination of both, so that the rider can slide forward and sit on the nose of the seat when in a forward position using the aerobars or when such a position is desired to recruit different muscle fibers. The width of the seat in the nose area and the amount of padding in that area, however, are limited by the rider's need to pedal unimpeded when sitting in the normal position. The practice of sitting on the nose of the seat, or anywhere forward of the optimized shape and padded area is generally a painful compromise for the athlete, perhaps delivering faster riding speeds for some, but at the expense of a sore buttocks, tail bone, and/or genitals. In addition, there are medical concerns about possible injury to the rider from concentrated and prolonged pressure to the genitalia caused by sitting on a narrow bike seat for extended periods of time.
Accordingly, what is needed is a bicycle seat with a mounting system, which provides for easy longitudinal adjustability of the seat position during a ride while minimizing the component weight, volume, and aerodynamic drag. Ideally, the bicycle seat mounting system should allow for compatibility with existing bicycle seat shapes and sitting surface designs, and existing seat posts and seat-post clamps so as to take full advantage of the products currently available in the marketplace as well as the advancements that can be expected in those product areas. Additionally, a vertical adjustment corresponding to the longitudinal position of the seat is desirable to maintain approximately the same distance between bike seat and pedals for any longitudinal position of the seat.